Last post on Feb 12, 2013 at 10:47 AM
You are in the Chevy Venture
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Chevrolet Venture, Engine, Van
#141 of 178 Re: 2002 Chevy Venture WB AWD [jeanz]
Dec 30, 2010 (7:05 pm)
Just out of curiosity, if you let the engine cool down to the point where you can remove the radiator cap, shouldn't you see fluid moving from the upper radiator hose (furthest from cap on top of the radiator) through the cooling fins back tot he lower hose once the thermostat opens?
I don't see any fluids moving on mine, my thought is water pump and/or thermostat. The top radiator hose gets warm but not hot, and the lower hose is ice cold. Only takes about 2-3 minutes for the engine to go from zero to 50%, then another minute to get to 75% of the gauge.
#142 of 178 Re: Fan problems [josechill]
Jan 05, 2011 (5:32 pm)
IMO, there is no issue with Dexcool and sludge. the "sludge" is an supplement/additative GM added to the coolant as "insurance". it's basically ground walnut shells, and ginger root. Cast aluminum is pourus, and this can seal up any micro leaks. this will easily pass thru any coolant system, and when it does, it'l be ground up by the water pump. when exposed to air, the mixture turns to a jelly like rubber sealant.
Second, I would suggest anyone that suffers from the cold coolant in the overflow, or temperature fluctuations, cold heet in cabin to have their thermostat changed, but have a 1/8 hole drilled into the outer portion of the t-stat. (between the thermo mechanism, and where the rubber gasket is. seems the 3.4 does indeed suffer from HG issues, but it is made worse by the fact that when the thermostat is closed (on a cold engine), or a running engine that's moving down a cold highway where the thermostat closes for some time. what happens is that tiny amount of air bubbles (less than a cup full) float up to the thermostats thermo sensor, and prevent the thermostat from properly detecting the temp of the coolant!. it varies, because if you make a turn, are on a bouncy road etc, the coolant will splash up & sometimes open the stat enough for you not to overheet, but you will see it on yor gauge as fluctuations. by drilling a hole, your 3.4 will indeed maintain it's 195 degrees, BUT any air trapped under the stat will be forced up to the highest point in the coolant system (luckily the cap), and as the pressure increases, it will be slowly expelled without damage to the overflow tank. Sometimes, small amounts of coolant will be dripped into the tank as well (even happens with a healthy engine), but during normal driving with acceleration, some of you know that the cooling system has a vaccume where it sucks in. - seen by a radiator hose collapsing a little or getting soft on a hot engine. - the good news is that the hose in the overflow tank is submerged in coolant, and it will suck that in, and not the air. as the pressure in the cooling system gets to operating temps, and 15psi, the amount of exhaust gases squeezed into the system diminishes. DO NOT USE HG IN A BOTTLE. you fill screw up the entire cooling system.
BTW, many cars have self purging systems that resolve this issue unfortunately not the 3.4 we must make it ourslves.
#143 of 178 2002 venture overheating, Cheap Fix! Quick and simply
Jan 28, 2011 (9:44 pm)
I might of found a very effective way of ilemminating the air pockets in the cooling system with out opening the bleed off valves all the time. My daughter has a 2002 Venture and has been having problems with over heating and no heat for defrosters or interior of the van. A mechanic changed the thermostat, but problem remand. Everytime we bleed the cooling system, it would go away for short periods and we had heat in the van. I had an idea, thinking of the old cast iron radiators in homes with the pressure relief valves, these are closed loop pressurized systems, and they had automatic bleeders to remove any air pockets, so why wouldn't this work on the van. Well, I found one thru a McMaster catalog for $26.78, Installed it and right away it started working as thew van should of. The valve is made by Maid-0-Mist and is called Auto-Vent No.78. All you have to do is remove the total bleeder assembly on the passenger side of the motor, and screw the automatic bleeder valve with the 1/8" NPT valve body directly into the bleeder port. Done, about three minutes and no more overheating problems and instant heat/defrosters in the van again. Doing research, it looks like you can order these automatic air eliminators right from your friendly Ace Hardware stores for a cost of $10.00 to $15.00 dollars.
#144 of 178 Overheating Ventures
Feb 23, 2011 (6:21 am)
Does anyone know the true answer to this problem???
#145 of 178 Re: 2002 venture overheating, Cheap Fix! Quick and simply [kellermeier]
Feb 25, 2011 (4:39 pm)
WOW KellerMeier - that's great you got this going. I am curious how this works out in the long run. I just did a Head gasket job on my Venture, and the gasket was intact, but the head had a small warp that the machine shop milled out. I'm sure your solution will work for many 3.4's that have a very minor amount of air entering the coolant - that reaks havic on the ability of the water pump to move the coolant thru the block. aside from the 1/16 drill hole in the stat, I also thought of using a 180 degree stat to keep the block 15 degrees cooler, and thus reduce the amount of expansion on the aluminum heads. Unfortunately because of emissions standards, it will be hard to find anyone who will match up a 180 to a 195 & sell it to you.
#146 of 178 Re: Overheating Ventures [ckelley1]
Feb 25, 2011 (5:30 pm)
#147 of 178 Re: Overheating Ventures [ckelley1]
Mar 31, 2011 (3:29 pm)
Yes. I know.
The 2 heads are aluminum & the block is cast Iron & each has a different rate of contraction & expansion. the head gaskets are made of multi layered steel (MLS). If the cooling system is not maintained properly (not kept full, car allowed to overheat etc.), air is trapped in the cylinder heads, and form hot spots, and the expansion/contraction is made worse. additionally the head gaskets themselve (steel), can begin to rust. All that is needed is a little leak between the cylinder portion of the gasket, and the coolant portion of the gasket, and you will get air pushing into the coolant.
think of it like this oIO where "O" is the cylinder, and "o" carries coolant thru to cool the engine block. if "I" rusts and breaks down, compressed air from "O" can now get into "o" and causes the car to overheat.
best advice if your Venture is OK is to keep that overflow tank filled to the line with 50/50 dexcool. If you have to keep filling it up, you have a leak, and you really should get it fixed. - these vans are really reliable if taken care of. Unfortunately for those of you who purchased 2nd hand, you have no trustworthy way to know how it was maintained. everything on this van is simple and straight forward.
#148 of 178 Re: 2002 venture overheating, Cheap Fix! Quick and simply [kellermeier]
May 27, 2011 (3:05 am)
Not calling you a liar as much as i'm calling myself stupid..If someone can be kind enough to explain i sure would be appreciative..The maid o mist thing is designed to vent at 75 psig and the radiator cap does the same thing at 15 psig or a whichever one it is.Soo how can the maidomist vent before the caps does??
#149 of 178 Re: High Temps in Coolant [russ23]
Jun 05, 2011 (3:40 pm)
Here's my experience with the 98 venture I own. After a year of overheating issues I replaced everything in the cooling system. Here's the list...radiator, hoses, heater hoses, engine coolant temp. sensor, relays (all 3) maf sensor, egr valve gasket, thermostat, water pump, upper and lower intake manifold gaskets (twice), the upper intake manifold (try finding one of those in a junk yard, tons of engines without the intake manifolds on them) and rebuilt ecm. After replacing all this the first few times it overheated (according to the gage) I 'bout blew my top. I took it to a reputable shop and has them diagnose it. They checked the block for minute cracks (none) and then let the engine run for 4+ hours to check the temp. It never overheated but the gage showed it running hot. The official verdict was this, since the coolant temp sensor AND the ecm were new, the sensor wasn't correctly calibrated so the ecm was reading that the engine was hot. Temp at the sensor was 225% when the fans came on. Runs great now, I just don't worry about the temp gage until I see steam!
#150 of 178 Overheating ALL the time
Aug 18, 2011 (5:57 pm)
How long should a radiator and water pump last?
2002 Chevy Venture runs hot all the time and recently got well into the Red zone.
Mechanic says its needs a new radiator and water pump but he did that 4 or 5 years ago.
Is 500.00 a fair price for this job?